Merchants can implement different types of payment systems in order to receive payments from customers. One type of payment system is a wireless and contactless payment system that uses near field communication (NFC) hardware and protocols. In an NFC-based contactless payment system, the merchant uses a reader device to wirelessly obtain payment information from a contactless payment device provided by the customer. The contactless payment device can include smart chip cards implementing the EMV (Europay, Mastercard, Visa) standard and portable electronic devices, such as smartphones or smart watches, that communicate via NFC and comply with payment standards.
In order to communicate with the contactless payment devices using NFC, the reader device emits a wireless carrier signal from an antenna, for example, at 13.56 MHz. The contactless payment device also has an antenna. When the contactless payment device is placed in close proximity to the reader, the two devices are inductively coupled via the wireless carrier signal. The contactless payment device is able to modulate the wireless carrier signal, for example, by modifying a load that is placed across the antenna of the contactless payment device. The reader device may receive the modulated wireless carrier signal from the payment device and process the signal to obtain the data from the payment device.
The reader device can be incorporated into a payment terminal that is used to process payment transactions and interact with payment devices. In order to ensure accurate processing of payment transactions, the reader device, and more specifically the NFC receiver of the reader device, has to accurately extract the payment information from the modulated wireless carrier signal sent by the contactless payment device. Merchants and consumers attempting to complete a payment transaction may become frustrated if errors occur during payment transactions or the payment transactions are not otherwise processed accurately due to the NFC receiver improperly extracting the payment information.